Welding machine



Dec. 11, 1951 Filed July 25, 1950 H. KERSHAW 2,578,074

WELDING MACHINE 4 Sheets-Sheet l Cttorneg Dec. 1l, 1951 H. KERsHAw2,578,074

WELDING MACHINE Filed July 25, 195o 4 fsheets-sneet 2 Dec. 1l, 1951 H.KERSHAW 2,578,074

WELDING MACHINE Filed July 25, 1950 4 Sheets-Sheet 3 :Snventor Bu Hzzrgfez'SLa/W attorney Filed July 25, 1950 4 Sheets-Sheet 4 TIMER ,/120 A*1&9/ Jmaenfor B7 1&1 l 173.3 D//IQO Henri] Kershaw a j Bu HO www "L 13Gftorneg M IERI] EWITCH Patented Dec. 11, 1951 UNITED STATES PATENTOFFICE WELDING MACHINE Application July 25, 1950, Serial No. 175,737

8 Claims. (Cl. 219-4) My invention relates to a welding machine.

An important object of the invention is to provide a welding machinewhich is extremely accurate in operation and is adapted to weld smallparts.

A further object of the invention is to provide means to closely adjustthe vertical distance between the pen point and balls.

A further object of the invention is to provide a, welding machine whichwill manipulate a writing pen and writing ball, and center the ball uponthe tip of the pen and weld these parts together.

A further object of the invention is to provide a welding machine whichwill produce a constant yielding pressure when the ball is applied tothe tip of the pen, so that the pressure will instantly follow throughduring the welding period.

A further object of the invention is to provide adjustable means toaccurately center the two metal parts being welded.

A further object of the invention is to provide means for holding a penpoint, to effect the welding operation, and to permit of the readyinsertion and removal of the pen point into and from the holding means.i A further object of the invention is to provide means for holding anumber of the writing balls and causing the electrode to remove a singleball and hold the same in a position to contact with the pen point.

A further object of the invention is to provide means which will permitof the free movement of the electrode, yet accurately guide the same insuch movement, so that the pressure will cause the movable electrode tofollow through during the welding period.

A further object of the invention is to provide means to automaticallyclose the welding circuit while the parts to be welded are underconstant pressure.

Otherlobjects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawings, forming a part of this application, and inwhich like numerals are employed to designate like parts throughout thesame:

Figure 1 is a front elevation of a welding machine, embodying myinvention,

Figure 2 is a side elevation of the same,

Figure 3 is a plan view of the machine,

Figure 4 is an exploded perspective view of the vertically movable tableand associated elements,

Figure 5 is a vertical section taken on line 5-5 of Figure 3,

vmi

Figure 6 is a similar view taken on line 6 6 oi Figure 3,

Figure 7 is a similar view taken on line of Figure 3,

Figure 8 is a vertical section taken on line 8-8 of Figure 3,

Figure 9 is a vertical section taken on line 9-9 of Figure 3,

Figure 10 is a vertical section taken on line l-I Il of Figure 3, partsin elevation,

Figure l1 is a vertical section taken on line of Figure 3,

Figure 12 is a horizontal section taken on line |2-| 2 of Figure 2,

Figure 13 is a horizontal section taken on line |3|3 of Figure 2,

Figure 14 is a side elevation of a micro-switch actuating rod andassociated elements,

Figure 15 is a diagrammatic view of the welding circuit,

Figure 16 is an enlarged fragmentary vertical section through theinsulating table showing the ball receiving recess, associated elementsbeing in elevation,

Figure 17 is an enlarged fragmentary side elevation of the pen point andball carrying recess, showing a curved cut at the end of the pen point,

.Figure 18 is a similar view showing a straight cut at the end ci thepen point, and,

Figure 19 is a side elevation of a completed pen.

In the drawings, where for the purpose of illustration is shown apreferred embodiment of my invention, the numeral 20 designates a hollowbase having a top 2|. The top 2| is provided at its rear end withvertical openings 22 for receiving insulating sleeves or bushings 23,having a press-nt therein. These bushings extend a slight distance abovethe top 2|. Having a press-nt within the bushings 23 are vertical posts24 projecting above the top 2| for a substantial distance, as shown. Itis thus seen Jthat the posts are rigidly mounted upon the base 20 andinsulated therefrom. Mounted upon the tops of the posts 24 is ahorizontal transverse crosshead 25, having knuckles 25 at its ends.These knuckles have openings 21, Figure l0, for receiving clamping bolts28 having screw threaded engagement within the upper ends of the posts24, which are preferably tubular. Arranged beneath the stationarycrosshead 25 is a vertically movable horizontal carriage 29, formed ofmetal and having a horizontal table 3|] rigidly secured thereto by bolts3| or the like. This horizontal table is formed of insulating material.The carriage 29 has vertical openings 3| formed therein receiv- 3 ingguide sleeves 32, having a press-fit therein, and these guide sleevesare slidable upon the posts 24. The guide sleeves engage compressiblecoil springs 33, surrounding the posts 24 and resting upon the upperends of the insulating sleeves 23. Rotatably mounted upon the crosshead25 is a horizontal longitudinal shaft 35, having Aa cam 35 rigidlymounted thereon, and operating within an opening 36, Figure l0, formedin the crosshead. This cam has a lower radial face 3l and an end face35, which is concentric with the shaft 34. The cam 35 is above and inalignment with a roller V3.9, secured to the carriage 29 by a pin di?,and operating in an opening 39. A segmental grooved pulley all isrigidly mounted upon the rear end of the shaft 34 and has a nexibleelement or cable .d2 secured thereto and passed about the same. Thiscable, when pulled downwardly, will turn the segmental pulley clockwise,Figure 10. This action will cause the radial face 3l of the cam toengage with the roller 39 and further movement Aof the camV 35 .bringsthe vcurved :end portion'SB of `the cam 35 into engagement with theroller 39. The carriage 29 is therefore lowered and reaches itslowermost position when the curvedend `face 33 engages .the roller 39,and further clockwise"turning movement of the shaft 35, Figure i0, vwillnot move the carriage29 .downwardly iurther. This is important since theselected yielding pressure is determined when Ythe Vcarriage 25 hasreached a selected lowered position and it is `not desirable that `thepressure -beincreased but should 4remain constant during the weldingperiod. The cable 42 vmay be moved downwardly by any :suitable meanssuch as a foot pedal. The shaft 341 is' turned counter-clockwise, Figurel0, `by means of a coil spring 43, Figure 11, one end Vof which isanchored to 'the shaft 34 vand its opposite Yend anchored to thecrosshead 2t. When `the cable 42 has been'moved downwardly and released,the shaft `34 is turned counter-clockwise by the spring 43,'so that theend face is umoved out of engagement with the roller 35 and the partswill assume the starting position, Figure Al.

The base top'Zl has a'large'cylindrical vertical opening 45toreceive acollar 56 of slightly smaller diameter. 'This collar is provided betweenits ends `with a horizontal flange 4l, resting upon the 'top2l. This.flange has verticalopeningsli to receive bolts 4,9 which 'are tappedinto the openings kl) in the top. The openings it are slightly larger indiameter than the bolts i3 so that .the sleeve 46 maybe slightlyradially adjustedupon the .top 2 l and subsequently clamped to the 1topin the `selected. adjusted position. An inner vertically Yadjustable`stop sleeve 5i `has a screwthreaded portion 52 to engage within thescrewthreaded opening of theouter'sleeve di. The adjustable stop .sleevehas an upperfknurled head 5.3, bymeansiof whichtheadjustable stop sleevemay be readily turned. Slidablymounted within thestop sleeve 5i Yisajtube vhhaving a radially enlarged end 5,5, providing an upperhorizontal shoulder 56 to engage with the-stop sleeve 5|. The enlargedend 55 carresafdepending extension 5l and the Vlongitudinal verticalslot 58 is formed in the enlarged lower end 55 and passes throughthe:shoulder 56. This slot receives `the V,end of a Screw 55 tapped intothe stop sleeve 45. VIn assembling, thetubetis inserted upwardlylthrough the lower end ofthe stop sleeve 5| and extends above thissleeve andthe vtube 54hasgac1osed end 63, carrying `an adjustable chuck.including a split socket 6l having its periphery tapered and threaded,to engage with the clamping ring nut 62. This chuck receives and holds alower vertical electrode 53, which may be formed of copper or the like.Mounted within the tube 5d is the metallic pneumatic bellows 64, whichvis longitudinally ex -pansible The upper end of this bellows is closedand contacts with the end 69. The lower end of the bellows is closed andis connected with a ypipe ,65leading into the bellows. This pipe extendsthrough an opening V5t formed in an inverted U -shape bracket 5l, havinghorizontal exH .tensions-53, which are secured to the lower edge of thesleeve 46 lby screws or the like. At its top, the bellows "bears againstthe end 53 and at its bottom against; the bracket 57.

Mounted within the hollow bottom 25, is a horizontal pressure reservetank $5, having the pipe 65 secured thereto by solder or the like. Acoupling 7l leads VVinto the ,outer ,end oi" the tan-k Se and isconnected with a valve lunit '32,. suchaspisgemployed upon a pneumatictire. li vbicycle pump or thelike may be connected with the valve unit'i2 to produce the desired air .pressure in the ',tankviii and bellows15,5. This v.pres-f sure will remain .constant except for slow :leakagewhich would require yadditional supply ot air pressure. The degreeoiairpressure is indicated by a guage l; connected vwith the tank 'Se 1,by apipe ld. ,I em-ploy 10W pressure in the welding and the pressure withinthe tank -and bellows vmay be vfrom l5 Ato .29 pounds ,per square inch.

Mounted gupon the insulating tablegil near the stationarycrosshead 25 isa base plate "i5, prod vided iat its longitudinal center with anopen-ing 'it for receiving a vertical pivot 'iii rigidly securedtothetable 35. This l.will .permit of a limited horizontal swinging movementof the base plate in opposite directions. V"llie horizontal adjust-Iment may be eiected by means oi a screw 78', arranged to Contact with laxed pin '35,- operaia ing ywithin an elongated opening de in the baseplate, and this fixed pin is rigidly ymounted-tillms the table 35. Thebase plate i5 a pair of large openings ,32, to receive clamping boltsB3, which lare rtapped into the table 135. -It is v thusseenthatthefbase plate maybe swung or adjusted about ;a vertical axis ineither ,directionV and clamped in the selected adjusted position.-

Arranged above the base plate 'i5 and formed integrall therewith lis ahorizontal vblock 'ii pro.-I vided near Yone .end :with a transverse`recess 85, slidablyreceivinga horizontal carriage 35. carriage 4is:providedvat one `end with a horizontal screw threaded opening 8l forreceiving a horizontalscrew Sit-.having a knurledihead 88. Thisscrewhasjagrooved hub Stengaging within Va slot 195 vformed `inafstationary :stop plate 555i, rigidly secured to the block 8G. It isthus-,Seen that .thezscrewli'i Ais freek to turn Ybutgcannot,movelongitudinally withrespeot to vthe block-and will longitudinally adjustthe carriage 86. The carriage is also provided vwith anelongated openingelto receive a verticalscrew 93 which is tapped intothe block'Sd. Itisthus seen that after the carriage has been longitudinally adjusted,itmay be clamped to the block in the selected adjusted position by meansof the screw 93. Formed'integralwith ythe carriage 35, is a dependingvertical holder block 94, provided upon its outer face with anupstanding recess :95, providedat its'lower end with a reduced extensionSS. The

v holder block is provided at its top Witha vertical A.arm 91, carryingan outwardly extendinghorizontal stop pin 98. The numeral 99 designatesa pen point. When the pen point is inserted into the recess, its reducedend passes into the reduced extension 06 and the upper end of the penpoint engages beneath the stop pin 98. Particular attention is called tothe fact that the central longitudinal axis of the pivot 11, the centrallongitudinal axis of the carriage 86, and the central longitudinal axisof the recess 95, are in alignment and remain in such alignment.

Disposed upon the front face of the block 84 is a horizontally swinginglever |0I, arranged between and pivoted to knuckles |02 by means of apin |03. Arranged upon that side of the pivot |03, next to the holderblock 94, is a plunger |05, slidably mounted in a transverse opening inthe block 84 and moved forwardly by a spring |00. The free end of theplunger |05 contacts with the lever |0I. When the lever is free, thisspring pressed plunger |05 swings the right end of the lever adjacent tothe holder block 94 outwardly from the holder block. The opposite end ofthe lever |0I engages a plunger |00, slidable in a horizontal transverseopening |01 formed in the block 84. The opposite end of the plungerprojects beyond the corresponding end of the block 84. The forward endof the plunger |00 engages the end of the lever |0| and its rear end isin the path 0f travel of a cam |01, mounted upon a horizontal pivot |08.This pivot is secured to the block 34. This cam has a radial arm |09,returned to the lowered position by a spring |09. When the radial arm isswung upwardly, the cam |01 moves the plunger |06 forwardly and thisplunger then swings the lever |0| upon its pivot s0 that the end of thelever next to the holder block 94 is shifted toward the holder block.The end of the lever IOI next to the holder block is oifset downwardlyforming a horizontal arm |01', carrying a laterally extending lug orfinger |02', movable into the reduced extension 06 of the recess tocontact with the reduced end of the pen point and clamp the same to thebottom wall of the recess 95. Arranged beneath and in alignment with thearm I 09 is a vertical trip shaft I I0, slidable within an opening |I|formed in the table 30. This shaft is provided at its lower end with alongitudinal bore I I2, to receive a rod I I3 slidable therein and acompressible coil spring ||4 is arranged within i formed in the top 2|and carrying a lock nut I I1.

It is obvious that the trip rod IIO may be vertically adjusted byturning the bolt II5. When the carriage 29 is moved downwardly the arm|09 of the cam |01 contacts with the rod I| 0 and the arm |09 is swungupwardly and the cam |01, through the medium of a plunger |00, will thenswing the lever I0| upon its pivot, so that the extension or lug |02will engage against the reduced end |00 of the pen point and clamp thepen point in place within the recess 95.

The insulating table 30 is provided upon its top with a tapered orconical recess or pocket 30a and has a vertical opening 30h which isconcentric with the recess 30a and leads into the bottom of this recess.A metallic guide sleeve or bushing 32a has a press-nt within the opening30a and receives the electrode 63. There is a slight clearance betweenthis electrode and the guide sleeve 32a such as .010 of an inch so lthatthe friction is reduced to a minimum between the electrode and sleeve32a. Arranged upon the top of the table 30 and extending diametricallythereof is a guide strip 33', formed of metal and this guide strip hasopenings 34 to receive screws 35 which rigidly attach the guide strip tothe table. The openings 34 are larger than the screws 35 whereby thestrip 33' may be adjusted within limits. This strip has a central head35a, provided with a central opening 34' and the electrode 63 enters theopening 34n when the table 30 moves downwardly. The electrode has asliding guide iit within the opening 34B, but the head 35 is relativelythin and the amount of friction between the contacting parts is reducedto the minimum, thus allowing the bellows to cause the electrode 03 toproperly follow through during the welding period. The balls or pelletsB which are formed of iridium have a diameter of .028 of an inch to .035cf an inch and these balls or pellets are held within the recess 30a.The upper end of the electrode 53 is tapered upwardly and this taperedend is pro-v vided with a spherically curved recess 630 for receivingthe lower portion of the ball which is held within the recess andprojects above the electrode. Due to the size of the recess 03a, onlyone ball B can be held upon the upper end of the electrode, and thisball is separated out from the other balls and is positioned above theguide head 35 when the table 30 descends. The lower portion of the baseplate 15 is cut away at 'l5' so that the base plate cannot contact withthe balls or pellets.

A heavy flexible wire IIB is connected with the base 20 by means of abinding post H9. This wire is in the form of a coil and its opposite endis electrically connected with the extension 51 of the stop sleeve 5|and hence in electrical connection with the electrode 03. Mounted withinthe base 20 is a micro-switch |25 including a button I2| adapted to bedepressed by a vertical switch rod |22. This switch rod is slidablymounted in an opening |23 formed in the carriage 20. This switch rodprojects above the carriage and is in the path of travel of a cam |24,clamped upon the front end of the shaft 30. The cam |24 is in a trailingposition with respect to the leading face 31 of the cam 35, when the camis turned to depress the carriage 29. The arrangement is such that thecam 35 will rst move the carriage 20 to the lowermost position and holdit in such lowermost positiony and shortly after this the cam |24 willdepress the cam rod |22 which will close the micro-switch |20. Themicro-switch remains closed until the carriage is returned to the upperposition.

As shown in Figure 15, the numeral |25 designates a step-downtransformer, having primary binding posts |26 and |21, and secondarybinding posts I 26' and |21. The binding post |26' is connected with awire |20 connected with a binding post 28a, Figure l, and hence the wire|28 is electrically connected with the pen point 99. The binding post|21 is connected with a wire 29 which is connected with a binding post||S and hence is electrically connected with the electrode E3. Theprimary binding post |20 is connected with a wire |3I, connected withone post |32 of the micro-switch. A lead wire |33 is connected with theother binding post |35 of the micro-switch. The other primary bindingpost |21 of the transformer is connected with the wire I 30 connectedwith one binding post |31 of a timer |38, and the other binding post |39of the timer is connected rwitn the opposite .lead -wire |453 Thepen-point 9,9 maybe stamped Vto provide a circularlycurved recess .99atthe lower end of the reducedportion or point |96. When this practiceis followed, the circularly curved recess 33a at the reduced end of theelectrode is of vgreater diameter than the ball B. The ball B willcenter itself by gravity in the recess 63a, and

vthen be capable .of moving laterally slightly therein whereby Vthe ballcan automatically center itself in the curvedrecess 9B. The lower end lof the vpen pointmay be stamped straight, asshown at Sila and whenv thispractice is followed the vrecess 33a is vformed of uasize to snuglyreceiVe the lower portionof .the ball, which cannot shift laterallywithin ,the recess 63a.

The operation of theapparatus is .as follows:

The springs,33 hold the carriage in theraised position, and the arm |9is in the lowered position. The spring 43 has returned the shaft 34 tothe starting position andthe cams 35 and |24 are in the raised position.The spring-pressed plunger Ilnow holds the lever ||l| in the outerposition whereby the clamping extension |2 is out of the reduced recessextension 96 of the pen receiving recess 95 and the plunger Iris shiftedtoward `the cam |07 and may contact therewith. Thepen 99 is theninserted into the recess 93, and itsreduced end enters the reducedrecess extension 96 and the edges of the pen ccntact with the side wallsof the recess and the upper end of the pen is positioned beneath thestop pin 98. The operator then pulls the cable 42 downwardly, bydepressing a pedal or the like. The carriage 29 descends and the end m9of the cam |61 engages the upper end of the trip rod Mil, having its'downward movement opposed by the spring H4. 'This trip rod swings thearm |99 upwardly and the cam |07 engages the plunger IBG and shifts thecorresponding end ofthe lever forwardly while its opposite end isshifted. rearwardly andthe extension lbrought into yielding clampingengagement with the reduced end of Vthe penfsecurely holding the penfrom moving out of the front open side of the recess 95. The stop pin 98prevents the upward movement of the penwithin the recess. The pen isalso held in good electrical contact with the holder block 94. Thisyielding clamping engagement is applied to the pen point before thereduced end of the pen point contacts with the ball B. The `continueddownward movement of the carriage 29 and table 30 causes the ball B heldwithin the recess 63a to be positioned above the guide head 35a and thereduced end of the pen IED is broughtinto engagement with the ball B andthe further downward movement of the pen point forces the ball Bdownwardly in opposition to theupward resilient or yielding action `ofthe bellows 164. Ayielding pressure is therefore applied between theball and the reduced end of the pen point. The radial face 37 vof thecam 35 moves the carriage to the lowermost position, which is defined bythe curved face 330i the cam riding upon the roller 39. Further .turningmovement of the shaft 34 will not cause the carriage 29 to move furtherdownwardly. This will provide a measured compression of the resilientbellows E4 .and a predetermined low pressure between the ball B and thereduced end itil of the pen pointsuch as'from 15 to 20 pounds per squareinch. Further slight turning movement of the shaft 3.4 will then causethe cam |24 to engage .the rod |22 which moves downwardly and actuatesthemicro-switch le20 which closes the welding circuit. The time that thewelding .circuit .remains closed is Acontrolled by the .timer |33 whichmay be .approximately from l .to .2 `5 .cyles, each cycle being 14;@ ofa second. The weld- ;ing current during this period is supplied to theball and the reduced end Ill@ of the pen point, and the contacting partsare welded by the metal :being plasticized, as is well known in welding.The ball is welded or fused to the reduced end of the pen point. Afterthe welding vhas been effected the pressure is'removed from the pedalandthe spring 43 returns the carriage to theraised position and all otherparts are returned to the normal startingposition. After the weldingcir--cuithas been opened by the timer, at the endof thewelding period,thetimer will not againclose the welding circuit until pressure is removedfrom .thebutton |2| of the micro-switch and the button vagain depressed.The clamping Yextension |02 of the lever ISI is nowshifted forwardlyfrom :the pen and this pen then manually removed from within the recesse5.

Before starting the welding operation, and be- `fore the vballs B areloaded in the recess-Bild, a pen point Q3 is inserted `into the recessand a gauge G is placedupon the top of the electrode-63 -fwhichfdoes notcarry a ball. The recess 63a is preferably -less in depth `than theradius of the 3o ball, and the 'recess 9S is also preferably .less `thantheradius of the ball. The .cable 32 ispulled downwardly to movethe-carriage 25 to the lower- .mostposition lf the gauge LG does vnotcontact .with the lower end of the pen point, the sleeve 35 `5| -isturned to raise the electro-de 63 until the vcontact -is made. IThe`rgauge preferably has a thickness less than the radius of the-ball.With the parts thus adjusted, the lower end of the p en .point will notcontact-with'the electrode'i, when .40 the carriage moves to thelowermost position, and the .electrode 63 does not carry a ball, so thatthe pen point will Vnot be welded to the electrode. It is obvious thatthe starting distance between the pen point and the electrode 63 may bevaried e5 vbyadjustingthe sleeve 5|, and hence the bellows .64 'will becompressed for differentdegrees, as Vmay be found advantageous.

After the ball :B is welded tothe pen point, the jpen point is formedinto the transversely curved shape and Yan opening 93a is stampedtherein. -The pen -point is then provided .with a slit 99h which is madefrom the opening 33a and extends through -the ball B.

It is to be understood that the form of my invention 4herewith shown anddescribed is to be taken as a preferred example of the same, and thatvarious changes in the shape, size, and arrangement of parts may beresorted to without :departing from the spirit of my invention or the`scope of the subjoined claims.

Having thus `described my invention, I claim: 1. In a welding machine, asupport, a substantially vertical stop sleeve having screw-threadedengagement with the support for vertical adjustment, a substantiallyvertical tube slidably mounted within the sleeve and having a part tocontact with the sleeve to limit the upward movement of the tube withrelation to the sleeve, a resilient pneumatic bellows mounted within thetube for opposing the downward movement of the tube, a relativelystationary element engaging the lower end of the pneumatic bellows forVholding such lower end against vdownward movement, a substantiallyvertical electrode mounted upon the upperend of the tube and extendingabove the 9' same, said electrode being provided at its upper end with arecess of a size for receiving a single ball, substantially verticalguide means mounted upon the support and extending above the tube, asubstantially vertically reciprocatory carriage mounted upon the guidemeans and including a part provided with a recess for holding the ballsand having a substantially vertical opening leading into the recess, theelectrode extending into the opening and being arranged within therecess and above the bottom of the recess when the carriage is moveddownwardly', a device connected with the carriage to reciprocatetherewith and arranged above the recess, said device including means forholdinga pen point with its reduced end disposed permanently lowermostand in subn stantial alignment with the ball held within the recess ofthe electrode', means to lower the carriage a predetermined distance andto raise the same, and a welding circuit electrically connected with theelectrode and the pen point holding device.

2. Inawelding machine, a support having a substantially verticalscrew-threaded opening open at its top and bottom, a substantiallyvertical stop sleeve having screw-threaded engagement within thescrew-threaded opening and projecting above the screw-threaded openingto be turned for vertical adjustment, a substantially vertical tubemounted within the stop sleeve and having its top closed and projectingabove the stop sleeve and having its lower end open and providedadjacent to such lower end with a shoulder to engage the lower end ofthe stop sleeve to limit the upward movement of the tube with relationto the sleeve, a resilient pneumatic bellows mounted within the tube foropposing its downward movement and having its upper end engaging theupper closed top of the tube, an element engaging the lower end oi thepneumatic bellows ior holding such lower end against downward movementand secured to the support, a substantially vertical electrode mountedupon the upper closed end of the tube and extending above the same, saidelectrode being provided at its upper end `with a recess of a size forreceiving a single ball, substantially vertical guide means mounted uponthe support and extending above the tube, a substantially vertically7reciprocatory carriage mounted upon the guide means and including a partprovided with a recess for holding the balls and having a substantiallyvertical opening leading into the recess, the electrode extending intothe opening and being arranged within the recess above the bottom of therecess when the carriage is moved f downwardly, a device for holding apen point with its reduced end disposed permanently lowermost, means tomount the device upon the carriage and arranging the pen holding deviceso that the held pen point will be in substantial alignment with theball held within the recess of the electrode, means to lower thecarriage a predetermined distance and raise the same, and means forelectrically connecting the welding circuit with the electrode and penpoint holding device.

3. ln a welding machine, a support, a substantially vertical stop sleevevertically adjustable mounted upon the support, a substantially erticaltube slidably mounted within the sleeve and having a part to contactwith the sleeve to limit the upward movement of the tube with relationto the sleeve, a resilient pneumatic bellows mounted within the tube foropposing the downward movement of the tube, a relatively stationaryelement engaging the lower end of the pneumatic bellows for holding suchlower end against downward movement, a substantially vertical electrodemounted upon the upper end of the tube and extending above the same,said electrode being provided at its upper end with a recess of a sizefor receiving a single ball, substantially vertical guide means mountedupon the support and extending above the tube, a substantiallyvertically reciprocatory carriage mounted upon the gui-de means andincluding an insulating table provided with a recess for holding theballs and having a substantially vertical opening leading into therecess, the electrode extending into the opening and being arrangedwithin the recess and above the bottom of the recess when the carriageis moved downwardly, a device for holding a pen point with its reducedend disposed permanently lowermost, means to mount the device upon theinsulating table and arranging the pen holding device so that the heldpen point will be in substantial alignment with the ball held within therecess of the electrode, a cam pivotally mounted upon the guide meansand having a radial face and a circularly curved face concentric withthe pivot ci the cam, means to turn the cam, the radial cam faceengaging a part of the carriage for moving it downwardly a predetermineddistance and the circularly curved face engaging such part withoutfurther moving the carriage downwardly beyond the predetermineddistance, means to raise the carriage, and means for electricallyconnecting a welding circuit with the electrode and pen point holdingdevice.

fl. In a welding machine, a support, a substantially vertical electrodemounted upon the support and provided at its upper end with a recess forreceiving a single ball, susbtantially vertical guide means mounted uponthe support, a vertically reciprocatory carriage mounted upon the guidemeans, a pen point holding device mounted upon the carriage for movementtherewith and including a block, said block being provided with asubstantially vertical recess open at one side for receiving a penpoint, said recess being provided at its bottom with a reduced extensionto receive the reduced end or the pen point, a stop element sen cured tothe upper end of the block and held stationary with relation thereto andextending across the recess to contact with the upper end of the penpoint, a horizontally swinging lever pivotally mounted upon the carriageadjacent to the open side of the recess and having its free end arrangedadjacent to the lower end of the recess and provided with an extensionto clamp against the lower end of the pen point, the major portion ofthe pen point extending above the free end of the lever so that the penpoint may be manually inserted and removed When the lever is in the openposition, automatic means to move the free end oi the lever to the openposition when the carriage is moved upwardly and to the closed clampingposition when the carriage is moved downwardly, means to raise and lowerthe carriage, and means for electrically connecting the electrode andthe block with a welding circuit.

5. In a welding machine, a support, a substan tially vertical electrodemounted upon the support and provided at its upper end with a recess forreceiving a single ball, substantially vertical means mounted upon thesupport, a vertically eciprocatory carriage mounted upon the guidemeans, a base plate, means to mount the base plate upon the carriage sothat the base plate may be angularly adjusted in a substantiallyhorizontal plane and locked to the carriage in the assez-0142 selectedadjusted' position, ak secondcarriage;

means to mount the second carriage uponi the base platei so that thesecond carriage can be shifted in a straight line in a substantially,horizontal plane transversely of: therbase plate. and locked to the baseplateinthe selected. adjusted position, a pen point holding blocksecured tothe second carriage and-having a substantially vertical recessformed therein having a reduced exten.- sionat its lower end,. therecess holding the: pen pointwith the reduced end ofzthepenpointiper'-manently in the lowermost position, releasable meansA for clamping thepen pointV within the` recess, means to raise andlower the carriage, andmeans for electricallyy connectingfthegwelding'cir. cuit with theelectrodeand the pen pointholdngi block.

6. In aweldingmachinda support, arsubstantially, vertical electr-odemounted upon the sup,- port, substantially vertical guide means mountedupon the support, a verticallyV reciprocatoryv carriagemounted upon theguide means, ,apen point holding device rigidly mounted upon thecarriage for movement therewith and having a recess for holding the penpoint with thev reduced end of the pen point arranged permanentlylowerrnost, ahorizontally swinging levery mounted upon the carriage andhaving an extension for clamping engagement with the pen point withinthe recess, means to swing thel lever in one direction so that itsextension has clamping engagement with the.

pen point including a cam having an extension, a spring to move the camto the inactive position, a trip rod arranged lbeneath the extension ofthe cam and in the path of travel oi the same to swing the cam to theactive position when the carriage is moved downwardly, a spring tooppose the downward movement of the trip rod and being stiffer than thefirst-named spring, means to raise and lower the carriage, and means forelectrically connecting a welding circuit with the electrode and the penpoint holding device.

7 In a welding machine,` a support, a substantially vertical electrodemounted upon the support and provided at itsv upper end with a recessfor receivingl one ball, substantially vertical guide means mounted uponthe support, a vertically reciprocatory carriage mounted upon the'guidemeans and including'A an engaging partand a table, said table beingprovided with a recess for receiving balls and a substantially verticalopening leading` into the recess, the opening receiving the upper end ofthe electrode, the upper end of the electrode being arranged within therecess so that the recess of the electrode picks Yup one ball when thecarriage is moved downwardly, a pen point holding device having a recessprovided with a reduced lower end for receiving the pen point andretaining the reduced end of the pen point permanently in the lowermostposition, a rock shaft mounted upon the upper end of the guide means, acam mounted upon the rock shaft and having a radial face and acircular-ly curved face concentric with the rock shaft, the cam beingarranged to engage the engaging part of the'carriage,` the radialiaceimoving the.V carriage down-,-V wardly forA a predetermin'edidistanceand.theciroularly/ curved face. preventing. the further downward movement ofthe-carriage after the action of the radial face, meansk to raise thecarriage, means toturn the rock shaft, a welding circuit' connected withthefpen point holding device and the electrode and including a switch,means to close the switch, andasecond cam mounted upon the rock shaftandhaving acam face for operating the switch closing means, the camfacet. of the second cam being arranged in a trailing position withrespect to' the radial face oi the first cam so that'th'e second camwill close the switch after therst'1cam-moves the carriage down-`wardly.

8. In'a weldingmachine, a support, a substantially vertical electrodemounted'upon the sup`- port and provided at' itsrupper end with arecess' for receiving aV single ball, substantially vertical guidemeansmounted upon the support, a

substantially vertically reciprocatory carriage' mounted upon the guidemeans and including a table having a recess for receiving the balls anda substantially vertical opening leading into. thev recess, thesubstantiallyy vertical opening being larger in diameter than theelectrode so that the electrode isvfree fromrcontact with the wall ofthe opening, a substantially horizontal thin guide strip mounted uponthe upper end of the table and having an openingvtc receive theelectrode and having a sliding t therewith, a pen point holding devicearranged above and in close relation to the thin guide strip and havinga recess iorreceiving the pen point with its reduced end' arrangedpermanently lowerinost, means to move the carriage downwardly so thatthe electrode recess picks' up a single ball and will pass into theopening of the4 thin guide strip and be accurately centered withrelation to the reduced end of the pen point, and means for connecting awelding circuit with the electrode and the pen holding device.

HENRY KERSHAW.

REFERENCES CITED The following references arcor" record in the leof thispatent:

UNITED STATES, PATENTS Number Name Date 1,061,378 Heany May 13, 19131,370,511 Boercker Mar. 8, 1921 1,490,191 Allcutt Apr. 15, 19241,548,397 Taylor Aug. 4, 1925 2,154,243 Langhams Apr. 11, 1939 2,299,543Humphrey Oct. 20, 1942 2,303,658 Jendressen Jan. 19, 1943 2,308,659Jendressen Jan. 19, 1943 2,355,576 Werfel Aug. 8, 1944 FOREIGN PATENTSNumber Country Date 544,047 Great Britain Mar. 25, 1942

